1. Field of the Invention
The present invention relates to an image communication apparatus having the function of checking a communication error.
2. Related Background Art
One type of conventional facsimile apparatus determines the quality of received image data on the basis of the number of bits between one line synchronizing signal and a next line synchronizing signal when the conventional facsimile apparatus effects G3 image reception according to the T4 recommendation of the CCITT (International Telephone & Telegraph Consultative Committee). The conventional facsimile apparatus then decodes the received image data, discriminates whether the number of bits corresponding to one line of image data is a predetermined number or not (i.e. whether the received line is correct or not), and then determines the quality of the received image data in accordance with a ratio of the number of correct lines to the number of incorrect lines. The conventional facsimile apparatus informs a destination of the quality of the received image data each time one page has been received.
However, the conventional facsimile apparatus has some problems, as follows.
In the case where the conventional facsimile apparatus has a laser beam printer (LPB) or the like and where the conventional facsimile apparatus records one page of the received image data at a fixed high speed, the conventional facsimile apparatus records a previous page while the apparatus is simultaneously receiving a next page. As a result, the conventional facsimile apparatus has to perform in parallel one decoding operation for checking the quality of the page being received and another decoding operation for recording the previous page stored in a memory, and a controller of the conventional facsimile apparatus has to be complicated and expensive.
Further, coding methods used in G3 facsimile apparatus are the MH (Modified Huffman) method and the MR (Modified READ) method. The conventional facsimile apparatus is easily able to decode the MH code, which is a one dimensional coding method. However, in the case where the conventional facsimile apparatus decodes the MR code, which is a two dimensional coding method, the process of decoding the MR code is complicated because of the need to process both a reference line and a current line in parallel. Thereby, especially, the structure for decoding the MR codes is complicated in the conventional facsimile apparatus.